Textile printing paste



Patented in, 7, 1942 UNITED STATES PATENT OFFICE Intenhemieal eorperationorobie x. mm. Application no 1:. 1m. I Serial No. W12

\ Claims.

This .invention relates to the art of textile printing, and is directed particularly to new tex-'- tile printing pastes comprising cellulose ethersolutions containing water solutions of dyestufls or dyestufi ingredients capable of producing permanent dyeings on fabrics, emulsified therein.

The conventional method of textile printing involves the application to a textile fabric of a dyestufi, or an ingredient of a dyestufi, in water solution, by means of an intaglio cylinder. In order to get the dyestufi' solution thick enough to remain in the cells of the printing cylinders, and to remain in place when applied to the fabric, water-soluble thickening agents such as British gum, starch and the like are used. More recently, wetting agents have been added to the pastes to improve their printing properties. Ai'ter printing, the dyes are set by various means so that they become water-insoluble, andthe fabric is washed to remove the water-soluble thickeners. Certain difiiculties are encountered with these conventional dyestufi' pastes. Since the fabrics printed are rather water-absorbent, prints made with water solutions, even when made viscous with the water-soluble thickeners, tend to spread out slightly from the point of application, a phenomenon knownas flushing. As a result, the lines in the engraving may become somewhat'blurred, and very fine lines close together may be entirely lost. When the viscosities of the pastes are adjusted so that no flushing occurs, the pastes become too thick to separate cleanly irom the engravings. A compromise must always be made, so that effective separation occurs without substantial flushing; and the cylinders must be so .prepared as to print most easily. Fine photogravure engravings have, as a consequence, never been used with conventional textile printing pastes, because their iaithiul reproduction of detail would not register on the fabric, Furthermore, the engravings used must be rather deep in order to get efiective printingfand considerably more pasteisusedthanisreally necessary to produce most designs.

Another disadvantage of conventional dyutui! pastes is that a substantial quantity of dyestufi may be washed out with the thickenei's. This is due partially to mechanical suspension oi converted dyestui! in the film oi thickenen partially to incomplete conversion of the dyestufi to the insoluble form, due to the trapping of the soluble dyestufi inside of the thickener film, and, income cases, partially to actual dyeing oi the thickener. This may represent a serious loss of dyestuil.

In my copending application, Serial Number 215,585, filed June 24, 1988, now United States Patent No. 2,202,283 or which this is a continuation-in-part, I have disclosed a means whereby these disadvantages may be overcome, and suc- -cessiuldyestuiifprintingcanbedcnewithphoto- 60 New York, R. It, a.

- gravure and other relatively shallow engravings,

withtheretentlonotthecompletedetall oithe photogravurecylmderaandtheuseot aminimum of dyastufi. Astherein disclosed,thismeanscoms prisesthepreparatim oidyestufipnnting pastes by the emulsification oi an aqueous solution of a dyestufi or a dyestufi component with a water immiscible bodying composition (preferably asolution of a film-forming thickener in a solvent),

10 the dyestufi solution being in the discontinuous phase. The resultant emulsion, of optimum consistency for printing, is applied to a fabric, as with a conventional intaglio cylinder; the dyestufi is fixed on the fabric, and the fabric is then is dried, with or without washing, depending on the dyestufi employed.

As the emulsion is applied to the cloth and the emulsion breaks, the dyestui! solution penetrates into the yarns o! the fabric. Since the water phase and the bodying agent are mutually repellant, the non-aqueous phase prevents undue spreading oi the aqueous phase. As a result, substantially no flushing occurs, and fine printing is obtained, which preserves the fine lines of a photogravure engraving even on materials which are as diilicult to mint as cotton fiannels.

I have now. discovered that unusually ellective results in this type of dyestui! printing can be obtained by using solutions of'cellulose ethers in hydrophobic organic solvents as the continuous phase of the emulsion, and particularly by using solutions of very small quantities oi cellulose ethers in hydrophobe hydrocarbon solvents. The ability of these cellulose ether solutions to as stably emulsiiy large percentages of water containing large quantities of electrolytes, and their resistance to decomposition by strong alkalis and acids makes them highly desirable for general use,

since they permit the use of dyestufis which re- 40 quire acid or alkali to put them into solution,

and likewise permit the incorporation of discharge agents ln the printing pastes.

Still another advantage oifthese solutions is that they produce stable emulsions or proper printing consistency with such very small quantiused, but materially hastens the operations.

The cellulose ether may be any one which is soluble in hydrophobe organic solvents, and is preferably one which yields solutions of high vis- -cosity in low concentrations. 5 High viscosity ethyl cellulose of the type used in ordinary lacquer work, having an ethoxy content oi 47.5% to49% andaviscosityoimcentipoisesorhigher (as conventionally measured at 25 (2., using s5% solutionotcelluloeeetherinamixtureoi low cost and resistance to acids and allralis. The

solvent should preferably be as volatile as is consistent with good printing practice, in order that as much as possible shall evaporate, so that it will have the least possible, action on the final finishing operations.

As indicated above, I prefer to keep the amount of cellulose ether ata minimum, to facilitate the finishing operations; but enough material must beused to produce a, stable emulsion. I have produced such emulsions with as low as 0.2% of high viscosity cellulose ether. I prefer to use not over about 2.0% of the ether to insure maximum ease of handling in the finishing operations, although higher percentages can be used.

In order to get a paste of printing consistency,

at least 20% of water is ordinarily required. In

general, larger amounts, of the order of 40 to 60%, are used by preference.

The following are typical examples of my invention:.

Example 1 Parts by weight 241 centipose viscosity ethyl cellulose .45 Pine nil .68 Xylol 13.85

Solvesso #2 (hydrogenated petrole m hydrocarbon, boiling range 135-177 C.) 14.27

Into this lacquer is stirred a mixture of- Parts by weight Rapidogen Red R solution (General Dyest'ufis Corporation, U. S. Patent No.

1,882,560) I 13.50 50% caustic soda solution 1.00 Water 56.52

This makes an exceptionally fine printing paste, which gives fine detail, and leaves practically no finish on the fabric.

Example 2 Parts by weight 241 centipose ethyl cellulose .40 Pine oil .21 302 xylol 12.09 304 Solvesso #2 12.30

Into this lacquer is stirred:

Parts by weight Ponsol Blue G. D. double paste (du Pont- Schultz 1234) 10.00 Glycerine A (General Dyestuffs Corporation) 4.00 Glycerine 6.00 Potash 9.00 Rongalite (formaldehyde sodium sulfoxylate) 8.00

Water 38.00

This vat dyestufi gives an exceptionally fast print which requires no Washing to remov thickener.

aaeaeca Other materials capable of conversion into fast fabric dyestuffs can be used to replace those shown, which are among the most diflicult to print because of the chemicals needed to keep them in solution. The vat dyestuff of Example 2 is set in conventional fashion, by oxidation; the "Rapidogen dyestuff of Examples 1 and 3 is set by acid treatment in conventional fashion. The use of my printing pastes permits this acid treatment to be effected in a wet way, thus eliminating the necessity for a special dry acid ager. The ordinary azo color salts, which are. printed on a fabric containing a base, and are coupled on the fabric, can also be printed easily with my pastes. I

Another advantage of my invention is that the printed material is immediately ready for the chemical treatment used to fix the dye, without further drying before treatment, as is required with conventional pastes. This makes possible a short, substantially continuous process of printing and fixing not heretofore attainable, since the steps of drying before fixing and removal of the thickener are eliminated.

' Other advantages of my invention will occur to those skilled in the art, and many modifications thereof can be made without departing from the scope of the invention, which is defined in the claims.

I claim:

1. A textile printing paste comprising an emulsion having a discontinuous phase comprising an aqueous solution of a water soluble textile coloring component, and a continuous phase comprising a solution of a water-insoluble cellulose ether in a volatile hydrophobe organic solvent.

2. A textile printing paste comprising an emulsion having a discontinuous phase comprising an aqueous solution of a water soluble textile coloring component, and a continuous phase comprising a solution of an ethyl cellulose in a volatile hydrophobe organic solvent.

3. A textile printing paste comprising an emulsion having a discontinuous phase comprising an alkaline aqueous solution of a water soluble textile coloring component, and a continuous phase comprising a solution of an ethyl cellulose in a volatile hydrophobe organic solvent.

4. A textile printing paste comprising an emulsion having a discontinuous phase comprising an aqueous solution of a water soluble textile coloring component, and a continuous phase comprising a solution of an ethyl cellulose in a volatile hydrocarbon solvent, the ethyl cellulose being present in said printing paste in an amount not exceeding about 2% by weight.

5. A textile printing paste comprising an emulsion having a discontinuous phase comprising an aqueous solution of an alkali and a water soluble textile coloring component, and a continuous phase comprising a solution of an ethyl cellulose in a volatile hydrocarbon solvent, the ethyl ceilulose being present in said printing paste in an amount not exceeding about 2% by weight.

6. The method of decorating or coloringtextiles which comprises applying an aqueoussolution of a textile coloring component to a textile fabric as a discontinuous phase dispersed in a continuous phase comprising a water insoluble cellulose ether dissolved in a volatile hydrophobe organic solvent, and immediately passing the fabric into a chemical treater to fix the color on the fabric.

NORMAN S. CASSEL. 

